Slipspace Effect
by deludemol
Summary: During the first annual "War Games" held between the UNSC and the Covenant Separatist Military, a UNSC battlegroup gets thrown into another universe, with a whole new enemy. Post Halo 4/Pre Mass Effect 3 by a few days. Alternate Universe. No Pairings.
1. Chapter 1

**UNSC **_**Infinity**_** Combat Sim, ****Epsilon Eridani, 2560**

Master Chief hit the dirt when plasma whined overhead. The rest of Blue Team, Fred-104, Kelly-087 and Linda-058 all had their armour paralyzed, and their radios gone silent – they were dead. Master Chief – John-117 – had peered over the mound of dirt in front of him.

He'd just barely got a look at the Sangheili Ranger when more plasma flew at him, causing him to hide again. He checked the counter on his MA5D assault rifle, which read 32. _Full. Good._ He thought while at the same time firing several bursts at the alien, causing it to take cover behind the barn like structure in front of him. He threw a frag grenade towards where he had last seen it, and his motion tracker saw the alien back away, but disappear. The one ton Spartan sprinted towards the structure and threw himself through the wooden wall, activating his VISR so he could see better.

It had outlined the alien in red, but before Chief could do anything about it, it had lept out at him. Demonstrating his lightning fast reflexes, he raised the rifle to the Sangheili's chest area and fired several shots at it; all of the bullets bounced off as if they were rubber, but it was slowing down. Then he saw the Sangheili's shield failed, and his weapon clicking several times indicating it was out of ammunition.

He improvised, ran up and hit it hard in the jaws with the butt of the rifle, causing it to fall onto its back and its own rifle skittered across the ground away from the two heavily armoured combatants. Chief had thrown his own rifle aside and the alien reached for its sidearm strapped to its hip, but he kicked it out of the hand of the alien and drawn his own sidearm, the M6H personal defense pistol and put a bullet through the aliens head.

At least, that what it seemed like, but they both knew they were in no danger. The buzzer had sounded and the weapons and scenery around them dissolved into nothing as the rest of Blue Team and Fire Team Redemption had gotten up. Chief helped up the Sangheili he had just defeated in an effort to demonstrate good will.

"Thank you, demon. It's an honour to battle such a skilled warrior." The alien, Rheun 'Lhoras had said. Even though their species had been at war for thirty years due to the lies of the San 'Shyuum, most of the Sangheili populous had allied with the humans against the rest of the Covenant when they had found that the humans were the reclaimers.

Master Chief had nodded, but remained silent. The Sangheili had made their way to the Phantom drop ship they arrived in, and Chief made his way to the cargo bay, where he spent his free time aboard the _Infinity_. Soon it would be time for the naval part of the first annual war games held between the Sangheili military and the United Nations Space Command. John sat down on a supply crate as the rest of his team walked in, hitting him on his shoulder plate as a congratulations. John simply nodded at the others, sliding back towards the wall, and rested his chin against the breastplate of his armour, nodding off.

**Bridge of the UNSC **_**Infinity**_**, ****Epsilon Eridani**

Admiral Thomas Lasky was reading the outcome of the previous day's skirmish, which caused him to furrow his brow. Fire Team Redemption had beaten Fire Team Majestic in the combat sim, causing an upset amongst his crew who had bet on Majestics win. It wasn't the win which bothered him; it was the fact that they were _creamed_. They only took out one of the sangheili which composed the five man squad, while they dropped like flies. He was interrupted from his thoughts when Roland, _Infinity's_ AI, appeared on the pedestal before him.

"Admiral, the results are in for the last of the skirmishes." Roland had said while the holographic avatar faced Lasky.

"Well, what are you waiting for?" he asked eagerly. He had a lot of credits riding on this match against Thel 'Vadam, the Arbiter.

"It was a very close match, and it came down to Sierra-117 and Rheun 'Lhoras, but Blue Team has emerged victorious, thus granting us the win in skirmishes of the war games." Roland said, his avatar 'smiling'. The bridge crew did a semi-professional cheer, and Lasky didn't blame them. He was beaming.

"Get me on the horn with Thel 'Vadam on the _Shadow of Intent_. I want to break the news to him before his team does." The AI held a hand up to its 'ear' then pointed at the Admiral when the Arbiter appeared on the main vidscreen.

"Admiral, to what do I owe the pleasure?" the four jawed alien said in English.

"Arbiter, the skirmishes are over. Your warriors are excellent fighters, but it was our Spartan-II's that prevailed in the end." The Admiral said.

"Very well, Admiral. I will wire exactly one thousand credits to your account at the end of the games. Shall I relay the message to the rest of my fleet to continue on and jump into deep space for the naval portion?"

"Yes, I will relay the message to the rest of the battle group and we will jump five minutes. Your fleet will coordinate and jump at the same time. Lasky out." And with that, the transmission was terminated. "Roland, you know what to do."

"Sir, I've already relayed orders to the rest of the battle group." The AI replied.

"Thank you, Roland." And with that, Lasky sat in the command chair. Lasky's mind began wandering, thinking about Requiem and thinking about his fleet, which consisted of 3 _Autumn_-class heavy cruisers, 5 _Marathon_-class heavy cruisers, 2 _Mako_-class corvettes, 3 _Halcyon_-class light cruisers, 9 _Charon_-class light frigates, 7 _Paris_-class heavy frigatesand the capital ship, the UNSC_ Infinity _has ten _Strident_-class heavy frigates in the sub hanger waiting to be deployed on a moment's notice. Forty ships in total.

The sangheili fleet, however consisted of the _Fleet of Retribution_ consisted of 9 _CCS_-class battlecruisers_; _the only one's name he could think of was the _Pious Inquisitor_; with the _Shadow of Intent, _a _CAS_-class assault carrier serving as the capital ship of their fleet.

The Admiral was snapped out of his thoughts when the deck started trembling violently. He gripped the arms of his chair tightly as alarms started blaring. He could see out the viewports that they were in slip space due to the stars, or lack thereof. The bridge quickly fell into a collective panic.

"Slip space communications down!" shouted O'Neil, the communications officer.

"Sir all weapons are offline!" shouted Mira, the weapons officer.

"Shields are down, trying to reroute non-necessary power to the shield generators." Roland said, calmly. Then next thing the crew knew, they exited slip space, all ships did. It had been thirty seconds, and the jump was fifteen minutes. Before anybody could get a grip on what was going on, one foot thick titanium slabs fell over the door to the bridge and over the deck windows. Lights had gone out and were replaced with red emergency lights. Before Lasky could process what had just happened, Roland's voice echoed through the bridge speakers.

"All major systems are back online with an exception to communications and our sensor suite. The Engineers are working on our sensors, and I am attempting to restore communications. Sir, what are our orders?" There was a piercing silence throughout the bridge.

"Alright, Roland use our tight beam communications to get the status of the other ships, including the _Intent_. O'Neil, establish inter-ship coms and get me a list of casualties, status reports on our fighters, pelicans, and the _Stridents_." Before anybody could get anything done, the alarms stopped, bright white lights flooded the previously dim bridge, and titanium slabs receded. The crew saw a very familiar sight. It was Earth. Everybody seemed to catch their breath in relief. But it was what Roland had said next that caught everybody's attention.

"I am detecting 77 vessels of unknown origin in defensive formation over the planet, ranging from corvette to destroyer class ships. Also sensors and communication are now online and the entire fleet is at full operational status." Roland paused. "Sir, Shipmaster R'tas 'Vadum has contacted me, asking whether or not to engage these unknown vessels."

"Tell him to not engage. I repeat: do **not** engage these ships unless fired upon first." He was cool on the outside, but on the inside, he was panicking. "Are they insurrectionists?"

"If they are, sir, then they are none the UNSC has encountered before."  
"Don't they just repurpose our own ships or use civilian freighters, Admiral?" Mira asked. Lasky just nodded in response.

"So, if they aren't insurrectionists, then who are they, and why isn't there any other UNSC vessels in the area, apart from our battle group?" he asked, starting to become irritated.

"Sir, they're launching several hundred strike craft!" Mira all but screamed.

"Damn it, Roland, send a fleet wide message, everybody stand by at their battle stations. Have teams of Spartans and marines ready to repel possible boarders. I want all Sabre wings on standby, and I want all _Stridents_ launched, and in a screen in front of the Infinity." The deck shuddered slightly.

"Stridents are away and Spartans and Sabres are on standby… it appears the strike craft have turned back and are holding formation with the other unknowns." Roland sounded relieved, even if his voice was synthesized.

"Put the unknowns up on the vidscreen." As they appeared on the vidscreen, he frowned. They reminded him of covenant, although they were missing the bulbous shapes and were much skinnier than covenant craft, they were just as sleek. They were mostly grey, with blue stripes on them and they had what appeared to be a blue arch with three stars in between them. Must be their insignia. "Give me firing solutions on the biggest one. And bring the _Infinity_ up on the holotank."

"Sir, they appear to be hailing us" Roland said.

"Put it on the main vidscreen"

**Bridge of SSV Kilimanjaro, 2186**

Admiral Steven Hackett nearly spilled his coffee all over himself when the emergency klaxons blared out. Half of First Fleet had just finished a refit cycle and was about to go back to the Charon relay to relieve them. He quickly looked to his XO, Captain Curt.

"Situation Report?" he said, trying to sound calm. Curt looked towards one of the crew, who answered his question.

"Admiral, forty unknown contacts have appeared from nowhere, 321,045 kilometers away at grid sector Bravo-452, ranging from frigate to… five kilometers?!" the ensign stammered. "What?" he said in disbelief, looking at the console for verification. What he saw visibly shocked him. Humanity's largest warship was the Kilimanjaro, which was 1.3 kilometers in length. But these…

"Ensign, bring them up on the holotank." He ordered. Bravo-452 appeared on the holotank; with thirty blocky grey vessels ten distinctly bulbous purple vessels appeared scattered. The grey ones looked ugly, but strangely human. The purple ones however were definitely alien in design. "Have they made any aggressive maneuvers?"

"No, sir. They might be dead in the water" Curt had said.

"Sir, the SSV Hawking has launched all fighters wings at unknowns, and…" the colour had drained from the ensigns face "… updating holotank now." What Hackett and Curt had seen had shaken them.  
"Not so dead in the water now…" Curt said, his voice barely audible. Not only had every single ship out there oriented their broadsides to face them, ten new contacts appeared on the holotank. "Ten cruiser-analogues launched from the five kilometer block one. All in a defensive formation around it."

Hackett had seen enough. He brought up his omni-tool; the glowing orange device covered his forearm, and raised it to chest height. "All Alliance vessels, this is Admiral Hackett. I did not give an order to engage these new contacts. We are **not** turians! Hold a defensive formation around Earth until further notice. Hackett out." There was a hint of poison dripping from his voice. The fighters turned back and placed themselves in the small gaps between each ship in the fleet to hold a defensive formation.

"Lt. Elaina, hail the one that launched the cruisers, all frequencies. I think we need an explanation from these newcomers, whoever they might be." He cleared his throat right after.

"Yes sir!" the communications officer of the Kilimanjaro began typing furiously into the only blue console on the dreadnought, "They're receiving… put it on the vidscreen, Admiral?" she asked. He nodded, and then the screen came to life, showing a human male who looked about fifty, wearing a grey uniform wearing admiral's stars and had a sidearm on his hip. His first assumption was Cerberus, but he remembered they only dress in white uniforms.

"Unidentified warships, you are in the territory of the Systems Alliance. Identify yourselves!"


	2. Chapter 2

**Bridge of the UNSC **_**Infinity**_**, Location: Presumably Sol**

Lasky massaged both his temples with his fingers as his anxiety started to show. He had no idea what was going on. _How could this be Earth?_ He thought. Suddenly the bridge filled with the sound of static, causing everybody to cover their ears. "What the hell is going on?" Lasky barked. The volume of the static went down, while everybody took their hands away from their ears.

"Sir, we're being hailed; I'm trying to isolate signal and clear it up as much as I can. Hold." Roland said. "And… close as I'm going to get it. Putting it on main vidscreen."

"_I s- aga-, unidentified warsh-ps,th-s is the SS- Kili-a-jaro, you are in the ter-tory of the Systems Al-iance, iden-ify yourselves!_" a man wearing what appeared to be a blue military officers uniform, with a cap that had a golden arch that was split in the middle with three gold stars inside said arch. In the background Lasky could see many crew members of the ship using orange consoles, some looking towards him.

"This is Admiral Thomas Lasky of the UNSC Infinity, and the United Nations Space Command. We have no hostile intentions."

The video feet cut out several times, then started swaying, like a 20th century VCR tape fast forwarding. "We're losing the signal. Whatever they're using, it's not compatible with our communications." Roland said.  
"_Uni-d N-tions S-ace C-and?_" The signal was degrading further. "_Infi-ty, I n-e- m-e infor-n -a- -"_

Lasky assumed that they could hear him. "Kilimanjaro, you're breaking up horribly. Suggest face to face meeting on a neutral ship. Do you copy?"

"_-opy tha-. We w- sen- a fr-gate to n-ral spa-e b-t-e-n us and y-u. H-ke-t ou-._"

Lasky sighed. "Roland, tell Sierra-117 to get to R&D, and let the techs there know to give him his gifts, and when he's finished he's to meet me at the main hangar. Also, tell the Arbiter we need him over here. If we're meeting with these people, we need representatives of both parties." Lasky paused a moment. "Did the _Port Stanley _come through with us? I know it wasn't officially part of the battle group, but I'm sure it was with us."

BB, the _Port Stanley_'s AI suddenly spoke up using the bridge's external speakers. "Yes, Admiral, we're here. Approximately 3.25 kilometers off your starboard."

Lasky wasn't surprised that BB left a fragment in the _Infinity_'s systems. He expected that from an ONI AI. "Great. Tell Captain Osman to put on her dress blues. We're about to meet with these people."

"She is already on her way and should be arriving at any minute. Anything else I can do for you, Admiral?"

"No, thank you BB." Lasky smirked.

**R&D Lab of the UNSC **_**Infinity**_

"How's it feel?"

John felt like he had gotten twelve hours of sleep. "It feels good." He replied, rolling his shoulders and moving his arms around.

The new Mjolnir Mk. VII[b] had all the same functions as the Mk. VII, such as the repair nano bots, the fusion-plasma hybrid power system, atmospheric insertion capabilities, slipspace de-insertion capabilities, active AI transfer protocols and the shaping of the energy shield, but was lighter, faster, and not as cumbersome. This was due to UNSC tech heads finding an intact Forerunner combat skin at ONI research facility Trevelyan. In addition to the lighter armour, it also came with an additional hardlight barrier over his energy shielding. The Mk. VII[b] also increases the users'strength and reaction time significantly, and it has thermal vision integrated into the VISR system.

He grabbed a MA5D off the rack and started to walk out the lab when he was stopped.

"Wait! I have something else for you." The tech called out. John turned around. "It's called the LSR44. It utilizes the new 7.62 hypersonic rounds, which during field tests have taken down Jiralhanae War Chieftain's shields in rather quickly and tear right through their armour and drag parts of organs out behind them." He said, handing the Spartan the white assault rifle. "Standard 32 round mags will fit into the back here, just like the MA5D, and there is little to no recoil on automatic fire, not that it matters."

John examined the weapon, noting the open top. _Probably a way to vent it quicker_, he thought. He made sure his M6H was on his hip before turning. "Thanks. I'm sure it will come in handy." The hulking warrior said. Once in the elevator, he could hear the sound of a Pelican landing, no thanks to his enhanced hearing and new helmet. He stepped out to a very tall ONI officer who he recognized but couldn't place a name to the face, Admiral Lasky and Naomi-010 in her steel blue Mk. VII armour, and also had a LSR44. They turned to face him.

He snapped to attention and saluted "Sir!"  
"At ease, Chief." Lasky calmly told him. "Did Roland brief you on what we're doing?"

"Yes, sir. First contact." The Spartan said, tensing slightly. "And we're security detail."  
"Sort of and yes." Lasky replied. "How rude of me. Chief, this is Admiral Osman, CINCONI. She will be attending the meet and greet with us. And I'm sure you remember Naomi-010."

He snapped to again towards Osman and when the courtesy was returned, he gave a curt nod towards Naomi and once again, the same was returned. Lasky walked towards John and led him away from the group. "Chief, I have one more surprise for you." He said as he led him towards a pedestal.

"Sir?"

"Well, I know you missed having an AI, so I got you one."

It had been three years since he lost Cortana.  
"Sir, will all due respect-"  
"Yes, I know, you don't want another AI. But this isn't just any AI." They stopped at a pedestal.

"Hi, Chief." He looked down, he hadn't heard that voice in three years.  
"Cortana? Is that really you?" He said, shocked. He was hesitant to believe that was the real Cortana.

"Yes, John, it really is me." She said, 'smiling'.

He turned to Lasky. "H-how?" was all he managed to choke out, turning to Lasky.

"Well, we managed to recover most of her data and 'memories' from the explosion over Earth, and she is now a fourth-generation AI. A perfect replica." He passed a data chip to the Spartan as he turned back to the pedestal. John paused and examined it for a moment, then looked to Cortana who was still 'smiling'. He smiled back under his helmet then held the chip out to her. She dissolved, and the centre of the chip glowed light blue. He inserted the chip into his neural interface in the back of his helmet, and he felt a chill run down his spine.

"You ready?" he heard Cortana say through his internal helmet speakers.

"Yes, you know what we're doing?" John replied.

"Mmhmm. Security detail for first contact."

"Let's hope everything goes smoothly."

John turned to find that Lasky had rejoined Osman and Naomi. He walked back to them, rifle in hand. Lasky put his hand to his ear, and then brought it back down a moment later. "Okay, they've sent a corvette to the designated meeting place, we're just waiting on-" he looked just past the Chief. "Speak of the devil and he shall appear."

The Phantom drop ship landed about five meters away from _Tart-Cart_, the transport Osman and Naomi arrived in, and the one they'd be taking over to the corvette now designated as '_Normandy_' by the lettering on both sides. Thel 'Vadam emerged from the Phantom and approached the group of humans.

"We've scanned the system, Admiral, and we are in the system designated as 'Sol', your home system." He stated. "We've also noticed strange gravitational readings around the unknown ships and from the edge of this system."

"We know, that's why we've called you here. We've arranged a meeting with these... unknowns... and they're human. They said they were sending a frigate to neutral ground, but we've detected a corvette out there, and we believe that is the meeting place. You will represent the Covenant Separatists."

Thel thought for a moment. "Very well, do we leave now?"

"Yes. We're leaving now." Lasky replied. Osman, Lasky, Thel, Naomi and John all piled into _Tart-Cart_ as the engine rumbled to life. The ramp sealed tight as the pelican took off from the hangar deck and thrusted forward into the vacuum.

Out of the corner of his eye, John saw Osman put what looked like a cube of crystallized ginger into her mouth and take a deep breath. He heard a female voice say over the comms in his helmet "Standby for slipspace transition".

* * *

**A/N: Sorry for the long wait, next chapter will be up in less time, probably. Don't forget to review!  
**


End file.
